• 치위생과학회지
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• 제15권4호
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• pp.488-494
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• 2015

치주인대세포의 효과적인 조절은 성공적인 치주 조직 재생에 중요한 역할을 한다. NFATc1의 활성화가 골모세포에서 분화를 자극하지만, 치주인대세포가 골모세포로 분화하는 과정에서 NFATc1의 역할은 아직 보고되지 않았다. 본 연구는 hPDLCs가 골모세포로 분화하는 동안 NFATc1의 mRNA의 발현과 단백질 발현이 유도됨을 처음으로 확인하였다. CsA에 의한 NFATc1의 억제는 세포증식을 감소시켰다. 게다가, CsA를 처리한 결과, 분화표지자, ALP activity 및 광화결정형성을 감소시켰다. 이러한 연구 결과는 NFATc1이 치주 재생을 위한 골모세포 분화에 중요한 조절자 역할을 할 수 있을 것으로 생각된다.

• Journal of Periodontal and Implant Science
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• 제41권4호
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• pp.167-175
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• 2011

Purpose: Periodontal ligament (PDL) cell differentiation into osteoblasts is important in bone formation. Bone formation is a complex biological process and involves several tightly regulated gene expression patterns of bone-related proteins. The expression patterns of bone related proteins are regulated in a temporal manner both in vivo and in vitro. The aim of this study was to observe the gene expression profile in PDL cell proliferation, differentiation, and mineralization in vitro. Methods: PDL cells were grown until confluence, which were then designated as day 0, and nodule formation was induced by the addition of 50 ${\mu}g$/mL ascorbic acid, 10 mM ${\beta}$-glycerophosphate, and 100 nM dexamethasone to the medium. The dishes were stained with Alizarin Red S on days 1, 7, 14, and 21. Real-time polymerase chain reaction was performed for the detection of various genes on days 0, 1, 7, 14, and 21. Results: On day 0 with a confluent monolayer, in the active proliferative stage, c-myc gene expression was observed at its maximal level. On day 7 with a multilayer, alkaline phosphatase, bone morphogenetic protein (BMP)-2, and BMP-4 gene expression had increased and this was followed by maximal expression of osteocalcin on day 14 with the initiation of nodule mineralization. In relationship to apoptosis, c-fos gene expression peaked on day 21 and was characterized by the post-mineralization stage. Here, various genes were regulated in a temporal manner during PDL fibroblast proliferation, extracellular matrix maturation, and mineralization. The gene expression pattern was similar. Conclusions: We can speculate that the gene expression pattern occurs during PDL cell proliferation, differentiation, and mineralization. On the basis of these results, it might be possible to understand the various factors that influence PDL cell proliferation, extracellular matrix maturation, and mineralization with regard to gene expression patterns.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제30권4호
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• pp.323-332
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• 2008

Aim of the study: Scaffolds are crucial to tissue engineering/regeneration. Biodegradable polymer/ceramic composite scaffolds can overcome the limitations of conventional ceramic bone substitutes such as brittleness and difficulty in shaping. In this study, poly(L-lactide)/hydroxyapatite(PLLA/HA) composite scaffolds were fabricated for in vivo bone tissue engineering. Material & methods: In this study, PLLA/HA composite microspheres were prepared by double emulsion-solvent evaporation method, and were evaluated in vivo bone tissue engineering. Bone marrow mesenchymal stem cell from rat iliac crest was differentiated to osteoblast by adding osteogenic medium, and was mixed with PLLA/HA composite scaffold in fibrin gel and was injected immediately into rat cranial bone critical size defect(CSD:8mm in diameter). At 1. 2, 4, 8 weeks after implantation, histological analysis by H-E staining, histomorphometric analysis and radiolographic analysis were done. Results: BMP-2 loaded PLLA/HA composite scaffolds in fibrin gel delivered with osteoblasts differentiated from bone marrow mesenchymal stem cells showed rapid and much more bone regeneration in rat cranial bone defects than control group. Conclusion: This results suggest the feasibility and usefulness of this type of scaffold in bone tissue engineering.

• Journal of Nutrition and Health
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• 제51권1호
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• pp.23-30
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• 2018

Purpose: Runx2 (runt-related transcription factor 2), a bone-specific transcription factor, is a key regulator of osteoblast differentiation and its expression is induced by the activation of BMP-2 signaling. This study examined whether zinc modulates BMP-2 signaling and therefore stimulates Runx2 and osteoblast differentiation gene expression. Methods: Two osteoblastic MC3T3-E1 cell lines (subclones 4 as a high osteoblast differentiation and subclone 24 as a low osteoblastic differentiation) were cultured in an osteogenic medium (OSM) as the normal control, Zn-($1{\mu}M$ Zn) or Zn+($15{\mu}M$ Zn) for 24 h. The genes and proteins for BMP-2 signaling (BMP-2, Smad-1/p-Smad-1), transcription factors (Runx2, osterix), and osteoblast differentiation marker proteins were assessed. Results: In both cell lines, BMP-2 mRAN and protein expression and extracellular BMP-2 secretion all decreased in Zn-. The expression of Smad-1 (downstream regulator of BMP-2 signaling) and p-Smad-1 (phosphorylated Smad-1) also downregulated in Zn-. Furthermore, the expression of the bone-specific transcription factors, Runx2 and osterix, decreased in Zn-, which might be due to the decreased BMP-2 expression and Smad-1 activation (p-Smad-1) by Zn-, because Runx2 and osterix both are downstream in BMP-2 signaling. Bone marker gene expression, such as alkaline phosphatase (ALP), collagen type I (COLI), osteocalcin, and osteopontin were also downregulated in Zn-. Conclusion: The results suggest that a zinc deficiency in osteoblasts suppresses the BMP-2 signaling pathway via the suppression of Smad-1 activation, and this suppressed BMP-2 signaling can cause poor osteoblast differentiation.

• 한국발생생물학회지:발생과생식
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• 제15권4호
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• pp.281-289
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• 2011

돼지 중간엽 줄기세포를 Dimethyl sulfoxide(DMSO), Ethylene glycol(EG), 그리고 DMSO/EG을 이용하여 세포동결을 유도한 후 적절한 동결보호제를 알아보았다. 2개월 이내 돼지 골수에서 중간엽 줄기세포를 분리하여 colony 형성 및 alkaline phosphatase(AP) 활성을 확인하고, 지방 세포로의 분화 유도에 의한 줄기세포의 능력을 확인하였다. 이들 중간엽 줄기세포의 완만 동결을 위해, DMEM에 각각 10% DMSO, 1.5M EG, 5% DMSO/0.75M EG의 동결보호제를 섞은 후 cryovial에 넣고, cryo-containe를 이용하여 $25^{\circ}C$에서 $-80^{\circ}C$까지 $-1^{\circ}C$/min 속도로 동결하였다. 일주일간 저장 후 세포의 생존률은 미동결 세포는 동결 세포군보다 유의적으로 높음을 확인할 수 있었으나, 동결 처리군 간에는 차이가 없었다. 줄기세포 유지 유전자인 Sox-2와 Nanog 발현은 동결 후 배양 시간에 따라 발현량이 증가하는 경향을 보였으나, 동결처리군 간에는 유의적인 차이가 없었다. 세포사 관련 유전자인 Bax의 발현은 모든 군에서 비슷하였다. 또한 지방, 연골 및 뼈세포 분화와 관련된 유전자의 발현은 동결 전 세포와 동결 후 세포군에서 비슷한 경향을 보였다. 이러한 결과는 돼지중간엽 줄기세포 동결함에 있어서 10% DMSO, 1.5MEG, 5% DMSO/0.75M EG 모두 적절한 동결보호제로 이용할 수 있음을 시사한다.

• 대한소아치과학회지
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• 제24권1호
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• pp.1-17
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• 1997

백서 태자 두개관을 효소처리하여 얻은 조골세포 유사세포군의 증식능 및 골결절의 형성에 미치는 dexamethasone의 영향과 형성된 골결절의 조직학적 형태 관찰을 위하여, 12 well 배양접시의 각 well 당 $4{\times}10^4cell$ 을 접종하였으며, 30일간 표준배양액으로만 배양한 군, 표준배양액에 ascorbic acid와 Na-${\beta}$-glycerophosphate를 첨가한 군, 그리고 각각에 dexa methasone을 첨가한 군등 4군으로 분리 배양하여 다음과 같은 결과를 얻었다. 1. 골세포의 증식율은 표준용액으로 배양한 군에 비해 dexamethasone 을 단독으로 투여한 군에서 약간 증가하는 경향을 보였으나 통계적인 유의성은 없었다 (p<0.05). 2. 골세포의 증식율은 ascorbic acid 에 의해 영향을 많이 받았으며, 특히 ascorbic acid와 dexamethasone을 동시에 투여했을때 더욱 현저히 세포증식율이 감소됨을 볼 수 있었다(p<0.05). 3. 배양 초기에는 세포들이 주로 섬유아세포 양으로 나타났으나, 밀생상태에 이르면서 점차 다각형 형태로 바뀌었다. 4. 배양 9일후 지방세포와 연골세포들이 관찰되었으며, 이들은 모두 dexamethasone이 첨가된 군에서 발견되었다. 5. 골결절은 ascorbic acid와 Na-${\beta}$-glycerophosphate가 첨가된 군에서만 형성되었으며, dexamethasone 을 병용첨가한 군에서 광화된 골결절이 현저히 증가됨을 관찰할 수 있었다. 6. 골결절 형성이 되지 않은 부위의 세포들은 평면형상을 이루고 있었으나, 골결절 부위를 덮고있는 세포들은 많은 세포돌기를 가진 조골세포양 세포들로 나타났으며, ascorbic acid, Na-${\beta}$-glycerophosphate 그리고 dexamethasone 을 첨가한 군에서는 침상의 돌기를 가진 광화물질들이 다발의 교원섬유들 사이에 현저히 많이 존재하였으며, 골결절 내부에는 매몰된 골세포(osteocyte)양 세포들이 관찰되었다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제32권3호
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• pp.199-206
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• 2010

This study investigated the effects of strontium on osteoblastic phenotypes of cultured human periostealderived cells. Periosteal tissues were harvested from mandible during surgical extraction of lower impacted third molar. Periosteal-derived cells were introduced into cell culture. After passage 3, the periostealderived cells were further cultured for 28 days in an osteogenic induction DMEM medium supplemented with fetal bovine serum, ascorbic acid 2-phosphate, dexamethasone and at a density of $3{\times}10^4$ cells/well in a 6-well plate. In this culture medium, strontium at different concentrations (1, 5, 10, and 100 ${\mu}g$/mL) was added. The medium was changed every 3 days during the incubation period. We examined the cellular proliferation, histochemical detection and biochemical measurements of alkaline phosphatase (ALP), the RT-PCR analysis for ALP and osteocalcin, and von Kossa staining and calcium contents in the periostealderived cells. Cell proliferation was not associated with the addition of strontium in periosteal-derived cells. The ALP activity in the periosteal-derived cells was higher in 5, 10, and 100 ${\mu}g$/ml strontium-treated cells than in untreated cells at day 14 of culture. Among the strontium-treated cells, the ALP activity was appreciably higher in 100 ${\mu}g$/ml strontium-treated cells than in 5 and 10 ${\mu}g$/ml strontium-treated cells. The levels of ALP and osteocalcin mRNA in the periosteal-derived cells was also higher in strontium-treated cells than in untreated cells at day 14 of culture. Their levels were increased in a dose-dependent manner. Von Kossa-positive mineralization nodules were strongly observed in the 1 ${\mu}g$/ml strontium-treated cells at day 21 and 28 of culture. The calcium content in the periosteal-derived cells was also higher in 1 ${\mu}g$/ml strontium-treated cells at day 28 of culture. These results suggest that low concentration of strontium stimulates the osteoblastic phenotypes of more differentiated periosteal-derived cells, whereas high concentration of strontium stimulates the osteoblastic phenotypes of less differentiated periosteal-derived cells. The effects of strontium on osteoblastic phenotypes of periosteal-derived cells appear to be associated with differentiation-extent.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제33권5호
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• pp.385-391
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• 2011

Purpose: The periosteum is a well-known source of osteogenic precursor cells for tissue-engineered bone formation. However, cultured endothelial or endothelial-like cells derived from periosteum have not yet been investigated. This study focused on endothelial-like cell culture from the periosteum. Methods: Periosteal tissues were harvested from the mandible during surgical extraction of lower impacted third molars. The tissues were treated with 0.075% type I collagenase in phosphate-buffered saline (PBS) for 1 hr at $37^{\circ}C$ to release cellular fractions. The collagenase was inactivated with an equal volume of DMEM/10% fetal bovine serum (FBS) and the infranatant was centrifuged for 10 min at 2,400 rpm. The cellular pellet was filtered through a $100{\mu}m$ nylon cell strainer, and the filtered cells were centrifuged for 10 min at 2,400 rpm. The resuspended cells were plated into T25 flasks and cultured in endothelial cell basal medium (EBM)-2. Results: Among the hematopoietic markers, CD146 was more highly expressed than CD31 and CD34. The periosteal-derived cells also expressed CD90 and CD166, mesenchymal stem cell markers. Considering that the expression of CD146 was constant and that the expression of CD90 was lower at passage 5, respectively, the CD146 positive cells in passage 5 were isolated using the magnetic cell sorting (MACS) system. These CD146 sorted, periosteal-derived cells formed tube-like structures on Matrigel. The uptake of acetylated, low-density lipoprotein, labeled with 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI-Ac-LDL) was also examined in these cells. Conclusion: These results suggest that the CD146-sorted positive cells can be referred to as periosteal-derived CD146 positive endothelial-like cells. In particular, when a co-culture system with endothelial and osteoblastic cells in a three-dimensional scaffold is used, the use of periosteum as a single cell source would be strongly beneficial for bone tissue engineering.

• 대한소아치과학회지
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• 제42권4호
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• pp.291-301
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• 2015

본 연구의 목적은 다양한 MTA 재료(ProRoot MTA, RetroMTA, Endocem Zr)에 대한 유치 치수 세포의 생활력 및 분화능을 비교 평가하는 것이다. 유치 치수세포는 각 재료별로 경화된 원형 디스크를 이용하여 직접법 및 간접법으로 세포 생활력을 관찰하였다. 또한 재료별 추출물을 이용하여 pH를 측정하였으며, alkaline phosphatase(ALP) 활성도 및 Alizarin Red S 염색법을 통하여 세포의 분화능을 관찰하였다. 직접법에서 유치 치수세포는 ProRoot MTA와 RetroMTA에서 Endocem Zr에 비해 높은 세포 생활력을 보였으나, 반면 간접법에서는 Endocem Zr에서 다른 재료에 비해 높은 세포 생활력이 관찰되었다. pH의 경우 Endocem Zr가 다른 두 재료에 비해 낮은 알칼리성을 나타냈다. 모든 재료에서 ALP 활성도는 대조군에 비해 증가하지 않았으며, Alizarin Red S 염색결과 유치 치수세포의 분화능이 대조군에 비해 낮았다. 본 실험에서 재료별 차이는 있었으나 모든 재료에서 어느 정도의 세포 독성이 관찰되었으며, 유치 치수세포의 생활력과 분화능을 증진시키지 못하였다. 하지만 Endocem Zr의 경우 ProRoot MTA나 RetroMTA에 비해 낮은 알칼리성과 높은 생활력을 보였다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제32권4호
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• pp.306-312
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• 2010

Purpose: The purpose of this experiment was to evaluate the clinical effect of cultured autoglogous osteoblasts as a way to treat the defect of mandible in rabbits. Materials and Methods: Twelve rabbits were used to determine the rate of osteogenesis. The osteoblasts were obtained from the iliac crest of rabbits using aspiration. They were then cultured in Dulbecco's Modified Eagles's Medium (DMEM) with beta-glycerophosophatate, L-ascorbicacid, and dexamethasone to proliferate and differentiate osteoprogenitor cells. The expression of osteogenic markers were detected by reverse transcription-polymerase chain reaction (RT-PCR) and silver nitrate staining techniques. Five, 10-mm holes were placed in each rabbit mandible to simulate defective regions with the use of a low speed trephine bur. In the experimental group, the previously cited defects were grafted with both activated osteoblastic and autogenous bone. The control group, however, was only grafted with autogenous bone. Both groups were then analyzed at 2, 4, and 8-week intervals using bone histomorphometric analysis. Results: According to histomorphologic analysis, the rates of new bone formation at the 2, 4, and 8-week intervals were 36%, 51%, and 23% for the control group, respectively; 52%, 39%, and 28%, for the experimental group, respectively. The experimental group showed higher rates of new bone formation compared to the control group at both the 2-week and 8-week interval. Conclusion: Bone marrow-derived osteoblasts seems to be a promising bone graft material.